Trophic role of ambush-foraging hydromedusae in the White seaстатья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 марта 2016 г.
Аннотация:Marine ecology 2012 (in the press
The purpose of this study was to determine the trophic role of three ambush-feeding hydromedusae inhabiting the White Sea, both in the natural environment (in the sea) and in an experimental system in the laboratory. Aglantha digitale (up to 35 ind* ), Bougainvillia superciliaris (up to 4 ind* ), and Sarsia tubulosa (up to 50 ind* ) were the most abundant hydromedusae species apart from Obelia spp. There was a variety of zooplankton prey in the stomachs of ambush-foraging medusae in the sea. A prey selection index С (Pearre, 1982) was positive and significant for copepod prey and Cirriped nauplii (B.superciliaris and S.tubulosa), for copepods, for cladocerans and for chaetognath eggs (A.digitale). In laboratory experiments, A.digitale was poor at capturing cirriped larvae. It may be that a deficiency in desmoneme nematocysts prevents A.digitale from retaining this prey. Diet, ingestion and digestion rates of these three ambush-foraging medusae did not agree completely. It appears that A.digitale has the shortest digestion time when compared to the anthomedusae. Individual predation rates in the sea were low for A.digitale in comparison with anthomedusae. B.superciliaris cleared 0.018-0.06 l*medusa*h with Oithona similis nauplii as a food source in an experimental setting. The average predation rate of medusae in the sea was in the range of experimental values. The prey with the latest onset of reproduction, such as eurythermous copepods, were the most affected by medusae predation. Also, anthomedusae feeding substantially increases mortality rates for cirriped larvae due to high selectivity for this prey.